Fluid temperature control device



Sept. 16, 1952 v. STREETER FLUID TEMPERATURE CONTROL DEVICE 2 SHEETS-SHEET 1 Filed June 9. 1950 frzI/E'r'd U17" Mcroe L Sneecrte Sept. 16, 1952 v. L. STREETER 2,610,795

FLUID TEMPERATURE CONTROL DEVICE Filed June 9, 1950 2 SHEETS-SHEET 2 37 fnFEz-zfar" V/croe L. SrEEETEe Patented Sept. 16, 1952 UNITED STATES- PATENT "creme,

Victor L. Strecter, Chicago, Ill. I Application June 9, 1950, Serial No. 167,097

6 Claims.

This invention relates to a pressure and temperature-sensitive mixing valve adapted to maintain a substantially constant selected outlet temperature irrespective of variations in inlet temperatures and pressures.

More specifically, this invention deals with a device for regulating the mixing of hot and cold liquids to produce a mixture having a preselected temperature and capable of maintaining this temperature throughout variations in the temperatures and pressures of the hot and cold liquids.

According to this invention, there is provided a temperature and pressure-sensitive mixing valve especially suitable for shower stalls wherein water of any desired temperature can be dialed by manipulation of a single valve and wherein variations in line pressures will not change the dialed temperature.

The valve of this invention will be hereinafter specifically described as embodied in a hot and cold water mixing valve for showers, but it should be understood that the invention is not limited in scope to any particular usage of the valve, since the principles of the invention are generally applicable to devices for delivering fluid at a constant preselected temperature from a plurality of sources of fluid at different temperatures.

The mixing valve of this invention includes a body with a hot water inlet, a cold water inlet, a mixing chamber, and a single outlet. Pressuresensitive valves control flow from the inlets to the mixing chamber. A manual control is provided with a valve to control flow to one of the inlets, a thermo-sensitive unit, a pilot valve, and a compensator. Actuation of the manual control first opens the manual valve to flow liquid to the first pressure-sensitive valve. The pressure of this liquid is eifective to open the valve in the other inlet. Fluids from both'inlets are mixed and flow to the outlet around the thermosensitive unit. If the temperature of the mixed fluid varies from the temperature for which the control is set, the thermo-sensitive unit expands or contracts to shift the pilot valve, thereby controlling the position of the valvein the first inlet to vary the proportioning of the liquids and produce a mixture of the temperature for which the control is set. In order to prevent hunting or over-control by the pilot valve, a compensator actuated by movementof the valve in the first inlet is provided to absorb some'of the effect of the shifting movement on the pilot valve produced by the thermo-sensitive unit or the manual A further object of the invention is .to provide a device for producing a stream of mixed fluids at a substantially constant mixture from a plurality of sources of fluids at different tempera- ,2 1. tures irrespective of variations in the pressures and temperatures of the difierent fluids.

Another object of the invention is to provide a mixing valve wherein a manual control first opens the valve and then selects a desired temperature for fluid discharged by the valve irrespective of variations in the temperatures and pressures of fluids supplied to the valve.

Another object of the invention is to provide a mixing valve especially adapted for shower stalls and the like wherein cold water inlet pressure must be developed before hot water can flow into the valve, and wherein a metering valve under the triple influence of manual setting, temperature setting,.and valve positioning, controls the position of the cold water inlet'valve.

A further specific object or the invention is to provide a compensator for a hot and coldwater mixing valve which varies the effective length of a control unit as the control unit imparts movement toan inlet valve so that temperature variations in the controlling cycle will be de-' creased. v

A still further specific object of the invention is to provide a hot and cold water mixing valve with a control unit including a shut-off valve, a thermo-sensitive unit, a pilot valve, and'a compensator for shifting the position of the pilot valve relative to the control member in response to shifting of a throttle valve controlled by the pilot valve, whereby overrunning of the throttle valve is avoided. Y

Other and further objects of the invention will be apparent to those skilled in the art from the following detailed description of the annexed sheets of drawings which, by way of a preferred example only, illustrate one embodiment of the invention.

On the drawings:

Figure 1 is a broken fragmentary elevational view of a mixing valve provided by this invention.

Figure 2 is a somewhat enlarged horizontal cross-sectional view takensubstantially along the line IIII of Figure 1.

Figure 3 is a fragmentary horizontal crosssectional view taken substantially along the line III-III of Figure 2, and on a furtherenlarged scale.

Figure 4 is a vertical cross-sectional view taken along the line IVIV of Figure 2 and shown on the same scale as Figure 3.

As shown on the drawings; I

In Figure -l,'the reference numeral if designates generally a hot and cold water mixing valve for shower stalls in accordance with a preferred embodiment of this invention. The valve is ineludes a body II with a cold water inlet i2 supplied by a pipe l3, a hot water inlet [4 supplied by a pipe iii, a mixed water outlet It discharging 3 handle I8. This valve I9 is used to control rate of flow of hot water and is also desirable as a safety shut-ofl in the hot water feed.

The mixed fluid from the outlet pipe I1 preferably discharges into the central portion of the bottom of a secondary mixing reservoir or tank 2I which, in turn, discharges through an outlet pipe 22 in the upper side wall thereof. The tank 2i is provided to hold a supply of mixed liquid from the mixing valve to further mix successive flow increments from the mixing valve to insure against a sudden change in temperature at the outlet 22 due to a changing of the valve setting or any changescaused by time delays in operation of themixing valve. Thus, for example, a

bather would notice a gradual rise or drop in temperature and would be ableto step out of the shower before being scalded or chilled.

The body I I has a bonnet I Iathreaded on one end thereof. and threadably receiving, a stem 23 therethrough. A. packingnut. 24 surrounds the externally projecting portion of the stemand. is threaded on thebonnetI Ia tohold packing material 25aroundthe stem as bestshown in Fig. 2. The handle.I8 is secured to theprojectingportion of the stem. Threads 23a on the stemmate with threadshl Ib in the bonnetsothatrotation of the stem will bev accompaniedby anaxial shifting of the stem. Thebody .I I has avalve seat 28in the end thereof. receivingthe, bonnet, and a valve head 23b on.the.stem.23.coacts.with the seat 26 to control flow from the bonnet into an inlet passageway 21 of the body- This passageway has a reduced diameter end. portion. 21a discharging into a mixing chamber 28.

The hot water inlet I4 also has a reduced.diameter cylindrical portion I'4a projecting into the chamber 28.

A cold water throttle valve 28. is pivotally mounted in the reduced; diameter passageway portion 21a and a hot water throttle valve is pivotally mounted inthereduced diameter passage portion I4a.. The valves 29 and 30 control flow-from the cold and hot water inlets into the mixing chamber. These valves are actuatedby pressure-sensitive diaphragms or bellows 3I and 32, respectively.

The bellows 3| has afixed end wall 3Ia spanning a chamber 28a inone end of the chamber 28. The housing II receives anendcap He in threaded relation thereon providing a chamber 33 for the bellows 3|. The opposite end..3I.b of the bellows is free. tomoveinJthe chamber 33 toward and away from the cap IIc. A stem or rod 34 is secured to the central portion of the free end wall 3Ib of .the bellows and depends therefrom into the chamber 28 to a point adjacent the reduced diameter portion 21a where it is pivotally connected to an arm 35 secured on the mounting pin 29a of the throttle valve 29. Thus, as the end wall 3Ib of the bellows moves toward the cap .I lo, the rod will be raised to swing the arm 35 for closing the valve 29. Conversely, as the end wall 3Ib moves toward the wall 3Ia. the rod will be shifted to swing the arm 35 in the reverse direction ;for opening the valve 29.

A diaphragm 36 is secured on the rod 34 and spans the inner end of the chamber 28a to seal off the chamber 28 from this chamber and provide a sub-chamber between the diaphragm and wall 3Ia of the bellows. The diaphragm 36 will shift with the rod 34 to vary the volume of this sub-chamber.

A second cap I Id-is provided on :the end of. the. body II opposite the cap IIc to'enclose the second bellows82 in. aseparatechamb'er 31. The

bellows 32 in the chamber 31 has its inner end wall 32a fixed on the body II. and its outer end wall 32b free to move toward andaway from the cap I Id. A rod 38 is secured to the central portion of this outer wall 32b of the bellows and is slidable through an aperture in the body to project into the chamber 28 and extend to a position adjacentthe reduced diameter inlet portion I4a where it is pinned to an arm 39 on the mounting stem 30a oi the hot water valve 30. A spring 48 surrounds the portion of the rod in the bellows 32 to urge the wall 32b toward the cap Nd, and thereby move the valve 30 into closed position.

A vent. 4I connects the passage 2'! in advance of the reduced diameter portion 21a with the chamber 31 to subject, the exterior of the bellows 32 to the pressure of the coldwater upstream from the throttle valve 29,and counteract the spring 40 for urginglthe valve '30 toward open position. a

The hot and-cold water. proportioned by' the throttle valves29 and 38, mixes inthe-chamber 28 and flows through apa ssage 42 (FigureB in the housing II to a chamber ;43 adjacentthe outlet IS. The control stem 23 extends into this chamber 43 and carries a thermo-sensitive bellows 44 in a position such that the-mixed hot and cold water from the passageway 42must flow around the bellows. enroute, to the outlet I6,

thereby insurin'ggood thermal contact. between;

the water and bellows. The bellows will elongate to increase the eifective length of the; stem when heated, and will contract to decrease the effective length of the stem when cooled.

The free end of the bellows carries a cup,- shaped. member 45 havingits open face spanned by a diaphragm 48 which is secured ;to. an outturned lip 45a around themouth of the cup. The

cup and diaphragm provide a chamber 4! which.

is vented to the chamber. through an opening 48. A spring 49 is compressed between the bottom of the cup and the central .portion :of the diaphragm to resist. collapse of the diaphragm into the cup. A pilot valve 5|! is slidably-mounted in a bore 5| of the housing. The hole connects the chamber 43 with. the chamber 28 and is aligned with the center of the. diaphragm. '46.

The pilot valve 58 is of the so-called dumb-bell" type. and includesv spacedheads 50a a'rxdillb "slidably engaging thewallxor. the bore 51 and reviding a localized chamber 52 'therebetween. in the bore.

stem and body-of the. valve have a continuous passage 54 therethrough' Joining the chamber 41" in the cup with aflexible tubel55 as. best shown. in Figure 2. One .endof the. tube-'55 is disposed.

over -a projecting. nubbin portion 'or. stem .portion of the pilot valve adjacent the .head soa, while the other end of the tubeisv s'ealingly anchored in the-diaphragm 35.. The chambers". and 28m are thereby inrcommunication through the pilot valve and flexible'tube.

The valve heads 50a and.50b arefiada'ptedsto respectively cover: and uncoverports '56. and '51 The localized chamber or space 52 betweenthe pilot valve heads -50a:and 50b. is connected through "a fpassagersll 'with the'cold water inletpassage 21. upstream from the throttle valve 29.

Thus. water fromfthis. passage =21: can selectively The valve. has a stem 53 Janchoredto. thecentral portion'oi the'dia'phragmxlii and thisv Operation It should beunderstood that the mixing valve of this invention, utilizes the inlet pressure of one fluid to open and manipulate the throttlevalve for controlling flow of the other fluid, and while the valve has been specifically described as usin cold water pressure to manipulate the hot water throttle valve, the inlets could be reversed to utilize hot water pressure for controlling the cold water valve without departing from the principles of the invention.

When the handle [8 of the valve is initially swung from its closed position, the stem 23 is shifted axially to unseat the valve 23b and permit water to flow from the inlet into the passage 21. This initial movement will preferably open the valve 23? to its full capacity. The safety valve I9 is also opened by rotation of the handle 2!! to permit hot water to flow to the inlet I4.

The handle [8 is then swung to a position for dialing the desired temperature of the water to be discharged. Suitable pointer and indicia arrangements (not shown) can be used. This movement of the handle will further shift the stem to position the pilot valve 50 relative to the ports 55 and 51. Cold water will flow past the throttling valve into the chamber 28, and the cold water pressure will be effective against the bellows32 to open the throttle valve for flowing hot waterinto the mixing chamber 28. The mixed water will thereupon flow through the passage to contact the thermo-sensitive bellows 44. If the temperature of this water varies from the temperature for which the valve handle l8 has been set, the bellows will expand or contract to shift the pilot valve 50 and either vent cold water tothe inside or the outside of the bellows 3i. p

As thebellows 3| expands or contracts, it shifts the rod 34 to'adjust the throttling valve 29 and control the rate f of discharge of the cold water into the mixing chamber. Thus, expansion of thermo unit 44 will shift throttle valve 29 toward open position to feed in more cold water. At the same time, the shifting rod 34 will change the volume of chamber 28a by movement of the diaphragm 36 and water will flow through the tube 55 and passageway 54 to conversely vary the volume of the chamber 45. These changes in volume of the two chambers will shorten or lengthen the effective length of the stem 23 to further adjust the pilot valve 50. Thus, as the valve 29 is moving toward open position, the volume of chamber 28a increases to draw water from chamber 41, thereby bowing diaphragm 46 inwardly to decrease the effective length of stem 23. This will shift the pilot valve 50 to vent space 52 with port 51, and thereby expand bellows 3| to move valve 29 toward closed position. The vent 48 will bleed water into or out of the chambers 28a and 45 when equilibrium has been reached and the spring 49 assumes its unstressed position shortly after the throttle valve 29 comes to rest.v This action of the opposed diaphragm chambers will compensate against over-control 6 of the throttle valve 29 and will decreasetempera ture variations in the controlling cycle. 7

,In the event of failure or materialdecrease of, pressure in the cold water passage 21, the pressure in the chamber 21 surrounding the bellows 32 will decrease, and the spring 40 will be effective to move the hot water controlling valve 30 toward, closingposition, thereby shutting off or decreasing the flow of hot water into the mixing chamber. This arrangement prevents scalding in the event of failure of cold water pres- Sure.

'Since the thermo-sensitive unit 44 only controls the cold water} throttle; valve 29, the rate of outflow is controlled by adjustment of the hot water valve l9.

The reservoir or secondary mixing tank 2| preferably isofsufficient volume tohold enough mixed liquid for a discharge flow of about five to eight seconds and is provided between the mixing chamber and the point of use of the mixed fluid as a safety factor to avoid any undesired sudden change in temperature at the outlet. The tank Will blend, successive flow increments of mixed liquid delivered by the mixing valve and, in turn, will deliver a, blended mixture to the outlet 22. The bather will, therefore, be proteoted against undesired extreme temperature variations. Thus, the bather would notice a gradual rise or drop in temperature due to a manual oversetting of the valve or time delays in functioning of the, valve under radical temperature or pressure variations in the valve inlets. The bather would therefore have sufiicient time to be able to adjust the valve setting, or step out of the shower before extreme temperature water is discharged. The tank also gives the thermo-sensitive unit suflicient time to react and control the temperature before any extreme temperature water can reach the outlet.

It will be understood that many departures can be made from the preferred hereinabove described embodiment. For example, bimetal thermostat elements could be used in place of illustrated bellows, the pilot valve couldassume many different forms other than the illustrated dumb-bell.

or spool-type valve, the cold water throttle valve could be spring'biased like the hot water throttle valve and actuated in one direction only by the pilot valve control, and the compensator could be arrangedin any way to act between opposed diaphragms or expansible members for varying the effective length of the control stem.

7 It is, therefore, to be understood that the invention is not to be limited beyond the scope of the herein appended claims, and that the language of the claims is intended to include equivalents for all 'of thespecified structures.

I claim as my invention:

1. A device for regulating the mixing of hot and cold fluids to produce a mixed fluid of preselected temperature which comprises a body having hot and cold fluid inlets, a mixing chamber and an outlet, first and second throttle valves controlling flow from the inlets to the mixing chamber, pressure-sensitive means for actuating the throttle valves, the pressure sensitive means for the first throttle valve having opposed pressure receiving sides for respectively opening and closing said valve, means biasing the second throttle valve toward closed position, the pressure-sensitive means for said second throttle valve being exposed to inlet pressure upstream from the first throttlevalve to oppose the biasing means for opening'sjaid second throttle valve, a

pilot valve for venting inlet pressure upstream ammo:

from the first throttle valve selectively to opposite sides of the pressure-sensitivemeans tor the first throttle valve, a control for shifting the pilot valve, 9. thermo-sensitive means inadvanceof the outlet for shifting said pilot valve in response to temperature variations, and acompensator actuated by movement or the first throttle valve for counteracting some of the shifting effect of the control and thermo-s'ensitive' 'm'eans" on the pilot valve to prevent overrunnin'g oi the first throttle valve.

2. A mixing valve which comprises a valve body having a cold water inlet, a hot water inlet and a single outlet, a-thr'ottle valve in each of said inlets, a manually shiitable' stem projecting into said body and accessible from'theoutside of the body, a shut-oil valve on said stem controlling flow to the 'cold- Water throttle valve, a thermosensitive unit on the stem, 5, pilot valve'slidably mounted in the body,.nieans defining a localized chamber between the theme-sensitive unitand the'pilot valve, a-diaphragm spanning said-chamber and connecting the .thermo sonsitive unit with the pilot valve, said pilot valve having a passageway therethrough, :pressuresensitive means for shifting the throttle valve in the cold water inlet, asecond diaphragm shiitable with said cold water inlet valve, means in'the body providing a closed chamber spanned by said second diaphragm, a flexible tube connecting said closed chamber with the passageway in the throttle valve to place both or the diaphragm chambers in closed communication, passageways selectively controlled by the pilot valvecormectingthe cold water inlet upstream fromthe coldwater throttle valveand downstream fromthes'hut-oif valve with opposite sides of the :pres'sure sensitive means for the cold water throttle valve, and spring-biased pressure se'nsitive means vented to inlet pressure upstream from the cold water throttle valve for holding open the hot water throttle valve.

3. In a mixing valve adapted to maintain a relatively constanttemperature .the improvement 'thermo-se'nsitive' means and .the pilot valve in communication with the first chamber for compensating movement'imp'arted to .the pilot valve by the thermo-sensitive means in accordance with movement of the throttle valve.

4. A device for delivering a stream of .fiuidrat a constant preselected temperature ,from a plurality of streams at different temperatures which comprises a body having throttle valve controlled low temperature and high temperature fluidinlets, means controlled by low temperature fluid inlet pressure for opening the high temperature fluid throttle valve, a device responsive to :pressures -on one side thereof for closing :the low temperature throttle valve and :responsive to pressures on the :opposite sidethereof :ior' o'pe'ning said low temperature throttle valve, a pilot valve exposed to low temperature flu'i'd pressure, a control for said pilot valve to selectively vent the low temperature fluid pressure to opposite sides of said device for controlling the low temperature fluid throttle valve, and :a compensator.between the control and pilot valveactuateaf y movement ofthe' low' temperature throttle valve 8 to decrease the effector the :control on .saidplow temperature'fluid throttle valve.

5. A temperature and pressure-sensitive mixing valve which comprises .a. body having a. plurality of inlets for: :fluicls or difierent temperatures, .a chamber :ior receiving said fluids :trom the inlets and outlet for said chamber, a throttle valve in eachihlet, Ea m'essureesensitive means for controlling each throttle valve, means venting to a first inlet flie pressure-sensitive means for the valve in a second inlet to open said valve under the influence of first inlet pressure, means'providing' a passage ior'venting first inlet pressure to the pressure-sensitive means-for the throttle valve in said first inlet, a pilot valve controlling flow throughsaid passage, whereby said throttle valve in the first inlet will vbe posicloned by first inlet pressure under the influence of the pilot valve setting, a control for sumin g said pilot valve, athermo-sensitive unit on said control for automatically shifting the pilot valve in response to temperature changes adjacent the outlet, and a compensator on said control connected with the pilot valve and actuated by movement of the throttle valve in the first inlet to shift the-pilot valve for absorbing 'the efieot of some of the shifting movement of the control and thereby preventing overrunning oi said throttle valve in the first imet. V

In amixing valve havingseparate inlets for cold and hot fluids, a mixing chamber and a common outlet, -a throttle valve in each inlet, spring-biased pressure-sensitive means 'urging the'throttle valve in the hot 'fiuid inlet-to closed position and being exposed to pressure in the cold fluid inlet for resisting the action .01 "the spring on the throttle 'valve, 1a pilotvalve vented to pressure in the cold fluid inlet, pressure-sensitive means having opposite sides thereof selectively vented 'to cold fluid inlet pressure by the pilot valve, a first'diap'hragm'movable with the throttle valve'in the cold fluid inlet, a chamber in said mixing valve closed by said .first diaphragm, a shiftable control stem, a thermo-sensitive means on Said control stem, a second diaphragm on said control stem, means .on 'saidcontrol stem defining a chamber closed by said second diaphragm between the thermo-sensitive means and said pilot valve, means joining the chambers closed by the first .and second diaphragms, and means for shifting said control stem, whereby the pilot valve will be moved in response to themovementor 'the stem and the thermo-sensitive means for selectively venting the cold fiuidr'inlet'pressureto opposite sides of the pressure-sensitive :means for operating the throttlevalve inrsaid cold.'fiuid inlet and whereby movement of said throttle'valve will effect shitting of the second diaphragm for :causing shitting'ofthefirst diaphragm to compensateagainst anoverrunnin-g of the throttle valve.in the cold fiuidinlet.

VICTOR L.

-REEERENCES 'CITED The following references are of record 'in the file of this patent:

UNITED STATES PATENTS Number Name Date 71,806,394 -Giesler -.et -al. ,May 19, 1931 .1,869;663 @Cartier Aug. 2, 1932 2,-2l4,-'147 :Scott Sept. 10, 1940 2,415,994, Curtis ..r Feb. 18, 1947 2,508,074 c-Miller et 'al. r IMay .16, 11950 

